feat: build core API, fraud engine, notifier, and frontend

Phase 1 — Core API (Go):
- Events, guests, tokens, RSVPs CRUD on PostgreSQL via pgx/v5
- HMAC-signed per-guest tokens with format validation
- Health endpoint with DB ping, slog JSON logging, graceful shutdown

Phase 2 — NATS + Fraud Engine:
- NATS JetStream pub/sub with explicit-ack consumers
- Python/FastAPI fraud engine with heuristic risk scoring
  (fingerprint mismatch, IP change, missing signals, repeated access)
- gRPC sync scoring with 250ms fail-open timeout
- Per-guest baseline tracking; risk bands low/medium/high/block

Phase 3 — Notifications + Frontend:
- Notification worker scaffolding (Twilio/SES stubs, retry/backoff)
- Nuxt 3 frontend with Tailwind dark theme + brand green
- Live monitor via WebSocket with auto-reconnect
- Activity history endpoint backfills monitor with RSVPs +
  scored access checks (including blocked attempts)

UX polish:
- Marketing-friendly landing page (hero mockup, how-it-works,
  features, use cases, testimonials, FAQ, final CTA)
- Animated layered card mockups on landing + new-event page
- Plus-ones stepper, RSVP status badges, filter buttons
- Friendly access-check labels (Verified/Review/Suspicious/Blocked)
- Dashboard hydration fix via ClientOnly wrapper

Infrastructure:
- docker-compose for full local dev (postgres, nats, api,
  fraud-engine, notifier, frontend)
- Multi-stage Dockerfiles, non-root UID 1000
- Integration tests with testcontainers-go

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/tailwind.config.ts

@@ -0,0 +1,35 @@
+import type { Config } from 'tailwindcss'
+
+export default <Partial<Config>>{
+  darkMode: 'class',
+  theme: {
+    extend: {
+      colors: {
+        brand: {
+          DEFAULT: '#22c55e',
+          50: '#f0fdf4',
+          100: '#dcfce7',
+          200: '#bbf7d0',
+          300: '#86efac',
+          400: '#4ade80',
+          500: '#22c55e',
+          600: '#16a34a',
+          700: '#15803d',
+          800: '#166534',
+          900: '#14532d',
+        },
+      },
+      fontFamily: {
+        sans: [
+          'Inter',
+          'ui-sans-serif',
+          'system-ui',
+          '-apple-system',
+          'Segoe UI',
+          'Roboto',
+          'sans-serif',
+        ],
+      },
+    },
+  },
+}